Establishment of the vernalization-responsive, winter-annual habit in Arabidopsis requires a putative histone H3 methyl transferase
Establishment of the vernalization-responsive, winter-annual habit in Arabidopsis requires a putative histone H3 methyl transferase
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DOI：
10.1105/tpc.105.034645
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发表时间：
2005-12-01
期刊：
影响因子：
11.6
通讯作者：
Amasino, R
中科院分区：
文献类型：
--
作者：
Kim, SY;He, YH;Amasino, R
拟南芥冬-年生植物的特点通常是需要暴露在冬季的寒冷中才能在春季开花。冷暴露前开花受阻是由于开花抑制基因C(FLC)的高水平所致。寒冷通过一种称为春化的过程促进开花，这种过程从表观遗传上抑制FLC的表达。快速循环材料通常具有低水平的FLC表达，因此不需要春化。对一年生冬季拟南芥转化为快速循环型的突变体的筛选已经确定了FLC表达所必需的推定的组蛋白H3甲基转移酶。这种甲基转移酶的损伤，短日早花(EFS)，导致FLC染色质中组蛋白H3Lys 4三甲基化水平降低。FLC分支中其他基因的表达也需要EFS，例如影响FLOWERING2和开花基因M的MADS。EFS需要允许几个FLC分支基因的表达，这解释了EFS损伤能够抑制由于FRIGIDA的存在、自主途径突变或非诱导光周期中的生长而导致的延迟开花。EFS突变体表现出多效性，表明EFS的作用不仅限于对开花时间的调节。
Winter-annual accessions of Arabidopsis thaliana are often characterized by a requirement for exposure to the cold of winter to initiate flowering in the spring. The block to flowering prior to cold exposure is due to high levels of the flowering repressor FLOWERING LOCUS C (FLC). Exposure to cold promotes flowering through a process known as vernalization that epigenetically represses FLC expression. Rapid-cycling accessions typically have low levels of FLC expression and therefore do not require vernalization. A screen for mutants in which a winter-annual Arabidopsis is converted to a rapid-cycling type has identified a putative histone H3 methyl transferase that is required for FLC expression. Lesions in this methyl transferase, EARLY FLOWERING IN SHORT DAYS (EFS), result in reduced levels of histone H3 Lys 4 trimethylation in FLC chromatin. EFS is also required for expression of other genes in the FLC clade, such as MADS AFFECTING FLOWERING2 and FLOWERING LOCUS M. The requirement for EFS to permit expression of several FLC clade genes accounts for the ability of efs lesions to suppress delayed flowering due to the presence of FRIGIDA, autonomous pathway mutations, or growth in noninductive photoperiods. efs mutants exhibit pleiotropic phenotypes, indicating that the role of EFS is not limited to the regulation of flowering time.